阅读说明：本技术 一种垃圾飞灰的资源化处置方法 (Resource disposal method for garbage fly ash ) 是由 赵洁 于 2020-04-12 设计创作，主要内容包括：本发明提供了一种垃圾焚烧飞灰零填埋处理技术领域,具体涉及一种垃圾飞灰的资源化处置方法。本发明包括化学预处理和制备高端水泥两个步骤。具体步骤如下：(1)将飞灰水洗过程中加入硫化钠、氯化亚铁、碳酸钠等溶液进行金属离子的脱除,来去除氯化物及重金属；(2)预处理后的飞灰通过密封管道气力输送到比较温度高的水泥窑尾中,随后进入到温度比较高的熔融中进行处置。同时在熟料熔融煅烧的时候,二噁英等难以去除的有机物彻底分解成二氧化碳和水蒸气。重金属也会被有效固定在水泥熟料晶格中,从而就确保了飞灰无害化、资源化的实现。(The invention provides the technical field of zero-landfill treatment of waste incineration fly ash, and particularly relates to a resource treatment method of waste fly ash. The invention comprises two steps of chemical pretreatment and high-end cement preparation. The method comprises the following specific steps: (1) adding sodium sulfide, ferrous chloride, sodium carbonate and other solutions into the fly ash in the water washing process to remove metal ions so as to remove chloride and heavy metals; (2) the pretreated fly ash is pneumatically conveyed to the tail of a cement kiln with higher temperature through a sealed pipeline, and then enters into melting with higher temperature for disposal. Meanwhile, when clinker is melted and calcined, organic matters such as dioxin and the like which are difficult to remove are thoroughly decomposed into carbon dioxide and water vapor. Heavy metals can be effectively fixed in the crystal lattice of the cement clinker, thereby ensuring the realization of harmless and recycling of the fly ash.)

1. A method for recycling garbage fly ash is characterized by comprising the following steps: (1) a chemical pretreatment part, namely adding sodium sulfide, ferrous chloride, sodium carbonate and other solutions into the garbage fly ash in a washing process to remove metal ions, and then removing harmful chlorine, sulfur and alkali compounds in the fly ash by a washing dechlorination process; (2) the dechlorination remainder can be used for preparing high-end cement, the temperature in a cement kiln can reach about 1400 ℃, organic matters such as dioxin and the like which are difficult to remove can be directly and thoroughly decomposed into carbon dioxide and water vapor, and main components such as CaO and SiO in fly ash₂、Al₂O₃Etc. are fully utilized as a part of the cement raw material.

2. A method according to claim 1, characterized in that an inorganic chloride removal process is added to the process.

3. The method of claim 1, wherein the control of dioxin phase and separation thereof during dechlorination of fly ash.

Technical Field

The invention relates to a resource disposal method of garbage fly ash.

Background

Domestic waste incineration is in a rapid development period in China, the production amount of fly ash generated by domestic waste incineration is rapidly increased, and the problem of fly ash disposal becomes one of the factors restricting stable operation of domestic waste incineration plants. The basic treatment modes of the garbage include landfill, composting, incineration and the like, wherein the incineration can lead the garbage to be sterilized at high temperature to achieve harmlessness, volume reduction of 90 percent and reduction of 75 percent, but a large amount of harmful substances such as soluble salt, dioxin, heavy metal and the like can be generated in the garbage incineration process, and secondary pollution can be caused by improper disposal. How to safely and effectively dispose the garbage fly ash becomes an environmental and social problem which needs to be solved urgently at present.

At present, the main treatment technologies of the waste incineration fly ash are as follows: cement curing, chemical stabilization, melt curing, and cement kiln co-processing.

The cement curing method is one of the most suitable treatment methods in view of economy, ease of handling, site utilization, and the like. Foreign researchers have conducted many studies on the treatment of fly ash by the cement solidification method, which is also one of the common methods for treating fly ash in foreign countries. However, the cement has a large capacity after the solidification treatment, and if fly ash contains a component which inhibits the normal setting of cement, problems such as low strength of the solidified body and high leaching rate of harmful substances often occur. The cement-based setting materials are classified into various types, and are generally used according to the characteristics and handling requirements of fly ash, and representative cements include ordinary cement and expansive cement, and are generally composed of silica-alumina and calcium oxide. The cement fixing method is to mix cement and fly ash with water uniformly to produce hydration reaction, gradually harden and seal harmful metals. In order to improve the fixing effect and ensure that the cement can effectively complete the hydration reaction, it is sometimes necessary to add appropriate additives to the mixture depending on the kind of fly ash.

The cement solidification method has the defects that the consumption of cement is high, and soluble chloride, sulfide and the like in the fly ash can have certain influence on the hydration process of the cement, so that the treatment effect of the fly ash is unstable. The treated solidified body has obvious capacity increasing and weight increasing, and the later treatment cost is increased.

That is to say, a large amount of fly ash is generated in the process of waste incineration, the fly ash contains high-concentration chloride salt, and the presence of the chloride salt can seriously limit the harmless disposal and resource utilization of the fly ash, which mainly comprises the following steps: 1) the chlorine salt can corrode the inner wall in the cooperative treatment process of the fly ash cement kiln, so that the cement kiln is blocked, and the quality of the obtained cement is greatly reduced; 2) when the fly ash is used as clinker, the dissolution of soluble chloride can influence the compactness and structural strength of a resource product and increase the leaching risk of heavy metals; 3) chlorine accelerates the corrosion of the steel reinforcement in the building material. Therefore, the cement solidification method alone has not been able to meet the demand for disposal of waste fly ash.

Disclosure of Invention

The invention provides the technical field of treatment of garbage fly ash, and particularly relates to a resource treatment method of garbage fly ash. The method comprises two steps of chemical pretreatment and preparation of high-end cement by dechlorination residues. The method comprises the following specific steps: (1) adding water into fly ash, adding sodium sulfide, ferrous chloride, sodium carbonate and other solutions under stirring to remove metal ions, and then washing; (2) the pretreated fly ash is pneumatically conveyed to the tail of a cement kiln with higher temperature through a sealed pipeline, and then enters into melting with higher temperature for disposal. Meanwhile, when clinker is melted and calcined, organic matters such as dioxin and the like which are difficult to remove are thoroughly decomposed into carbon dioxide and water vapor. Heavy metals can be effectively fixed in the crystal lattice of the cement clinker, thereby ensuring the realization of harmless and recycling of the fly ash.

Detailed Description

The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

In the present invention, the raw materials and equipment used are commercially available or commonly used in the art, unless otherwise specified. The methods in the following examples are conventional in the art unless otherwise specified.